The present invention generally relates to a musical tone control apparatus, and more particularly to a musical tone control apparatus which controls a musical tone in response to a body action and a hand or arm swinging action of a player when the player practices a rhythm gymnastics.
As well known in an electronic keyboard musical instrument, the player operates keys and several kinds of operating elements for controlling musical tones by use of his hands and feet to thereby select a desirable tone pitch, a desirable tone color and the like, for example. Thus, the player plays the electronic keyboard musical instrument.
Meanwhile, the electronic keyboard musical instrument can not select the tone pitch without depressing the keys by his hands or feet. Hence, the performance method of the musical tone must be limited.
Therefore, the present applicant proposed a musical tone control apparatus (i.e., U.S. patent application Ser. No. 108,205) which controls the musical tone to be generated in response to the hand or arm swinging action of the player. Next, description will be given with respect to a first example of this proposed musical tone control apparatus in conjunction with FIGS. 1 to 5.
In FIG. 1, a base portion 1a of a stick 1 is held by a player's hand H, and an angle detector 2 (or an angle sensor 2) is equipped within a tip end portion 1b of the stick 1.
As shown in FIG. 2, the angle detector 2 is constructed by a support plate 3 and four mercury switches "a" to "d" fitted to the support plate 3. These mercury switches "a" to "d" have respective center axes Ja to Jd which form respective angles of 22.5 degrees, 67.5 degrees, 112.5 degrees and 157.5 degrees with respect to a reference line L. Each of these mercury switches "a" to "d" is constructed by a glass tube 4 in which a certain quantity of mercury liquid 5 as shown in FIG. 3 is sealed. Both end portions of this glass tube 4 are tightly closed, and a pair of electrodes 6a and 6b are inserted through one end portion of the glass tube 4 by certain lengths thereof. In a state shown in FIG. 3, the mercury liquid 5 does not turn on the electrodes 6a and 6b because the electrode 6a does not come into contact with another electrode 6b via the mercury liquid 5. As the mercury switch shown in FIG. 3 is revolved in a direction A, the mercury liquid 5 will turn on the electrodes 6a and 6b.
When the angle detector 2 shown in FIG. 2 is revolved around a reference point O, some of the mercury switches "a" to "d" will be turned on in a manner as shown in FIG. 4. First, in an initial state as shown in FIG. 2, all of the mercury switches "a" to "d" are turned off. Secondly, the angle detector 2 is revolved by 45 degrees around the reference point O in a direction B (i.e., a counterclockwise direction) so that the mercury switch "a" is only turned on. Thirdly, the angle detector 2 is further revolved by 45 degrees around the reference point 0 in the direction B so that the mercury switches "a" and "b" are turned on. Similarly, at every time when the angle detector 2 is revolved by 45 degrees around the reference point O in the direction B, the mercury switches which are turned on will be changed as three mercury switches "a", "b" and "c"; the four mercury switches "a" to "d"; the three mercury switches "b", "c" and "d"; the two mercury switches "c" and "d"; and the one mercury switch "d".
Next, FIG. 5 is a block diagram showing a first example of the proposed musical tone control apparatus. Based on on/off states of the mercury switches "a" to "d", a musical tone control circuit 7 detects an angle of the angle detector 2 against the ground, i.e., a swinging angle of the player's hand H holding the stick 1. Hence, the musical tone control circuit 7 outputs tone pitch data KD corresponding to the detecting result thereof. Such tone pitch data KD are supplied to a musical tone signal generating circuit 8 wherein a musical tone signal corresponding to the tone pitch data KD is generated. This musical tone signal is outputted to a speaker 9, whereby the speaker 9 generates a musical tone having a tone pitch corresponding to the swinging angle of the player's hand H.
In the above-mentioned first example of the proposed musical tone control apparatus, the following problems (1) to (5) occur.
(1) In the case where an additional switch is equipped to the stick 1 so as to selectively change the tone color of the musical tone, only one or two switches are considered to be equipped to the stick 1 because of the shape of the stick 1. Hence, this former musical tone control apparatus suffers a problem in that it is difficult to arbitrarily change the tone color of the musical tone by use of such a few switches.
(2) The angle detector 2 within the stick 1 can detect the arm swinging angle of the player with accuracy when he swings up his arm with a relatively slow speed. However, when the player swings the stick 1 violently with a high speed, the angle detector 2 can not detect the arm swinging angle of the player with accuracy. In such case, an acceleration sensor is considered to be used for detecting a violent movement of the player's arm because this acceleration sensor can output a signal having a level corresponding to the acceleration applied thereto, for example. However, the stick 1 according to the former musical tone control apparatus can be equipped with only one sensor. Hence, the former musical tone control apparatus is burdensome in that this apparatus must provide two sticks which are equipped with the angle sensor and the acceleration sensor independently.
(3) In each of the mercury switches "a" to "d", the mercury liquid 5 turns on or off the electrodes 6a and 6b because the mercury liquid 5 normally moves downward under an effect of the gravitation. Hence, when the player swings up and down his hand H holding the stick 1, an impulse force and a centrifugal force have an effect on the angle detector 2 remarkably. For this reason, the angle detector 2 may commit an error operation. In addition, a minute movement or vibration of the player's hand H is likely to be amplified to a relatively large movement or vibration at the tip end portion 1b of the stick 1. As a result, the angle detector 2 may commit an error operation again.
(4) Meanwhile, the player's arm can freely move and revolve around his shoulder joint. Considering for a revolving movement of the player's arm in his right or left direction, his hand traces along an inner periphery of an imaginary circular cone having a top of the shoulder joint, for example. In addition, when the player revolves his arm sideward, the stick 1 must be twisted in accordance with a twisting movement of the player's wrist because of constructions of joints of his arm. For this reason, the angle detector 2 can not detect the arm swinging angle of the player with accuracy. More specifically, when the angle detector 2 is revolved within a two-dimensional plane including the plane of the support plate 3, the angle detector 2 can detect the swinging angle of the player's arm with accuracy. On the contrary, when the above-mentioned twisting movement of the player's wrist causes the support plate 3 to revolve in a direction perpendicular to the plane of the support plate 3, the angle detector 2 can not detect the swinging angle of the player's arm with accuracy. Furthermore, since the mercury switches " a" to "d" are arranged radially around the reference point O, the scale of the angle detector 2 must become large.
(5) Due to the above-mentioned arrangement of the mercury switches "a" to "d", the player must hold and keep the stick 1 such that the support plate 3 must be normally located within the two-dimensional plane including the plumb line, whereby the stick 1 functions as the musical tone control apparatus.
However, since the stick 1 has a cylindrical shape as shown in FIG. 1, the player can hold the stick 1 as he likes. For this reason, it is difficult to recognize the direction in which the support plate 3 of the angle detector 2 faces.
Next, description will be given with respect to a second example of the proposed musical tone control apparatus in conjunction with FIGS. 6 to 9.
FIG. 6 shows an essential appearance of this second example of the proposed musical tone control apparatus which controls the musical tone in response to the body action in the rhythm gymnastics and the like. In FIG. 6, a stick S having a cylindrical shape provides a key-on switch 11 equipped near a holding portion thereof. The player puts a mounting wear W on an upper half of his body, and a supporter P made of flexible materials such as rubber is mounted at a shoulder joint portion of the mounting wear W. As shown in FIG. 7, a potentiometer 13 of an angle detector 12 is mounted around a center portion of the supporter P. One edge portion of a lever 14 is fixed to a shaft 13a of the potentiometer 13, and the other edge portion of the lever 14 can be freely put in and out from a cylinder 15 as shown in FIG. 8. Within an inner portion of the cylinder 15, a spring 16 is provided in order to pull the lever 14 therein. In addition, a fixing portion 15a is formed at an edge portion of the cylinder 15 and mounted at a certain upper arm portion of the mounting wear W.
When the player swings up his right arm shown in FIG. 6, the lever 14 and the cylinder 15 are revolved in response to the swinging movement of the player so that the shaft 13a must be revolved. Hence, the revolving angle of the shaft 13a corresponds to the arm swinging angle of the player, and the angle detector 12 outputs a detection signal C1 corresponding to the arm swinging angle to an angle detecting circuit 17 shown in FIG. 9. The angle detecting circuit 17 generates angle data KD the value of which corresponds to the level of the detection signal C1, and such angle data KD are supplied to a musical tone control circuit 18. This musical tone control circuit 18 monitors the on/off states of the key-on switch 11 mounted on the stick S. When the musical tone control circuit 18 detects that the key-on switch 11 is turned on, the musical tone control circuit 18 generates key-on data KOD and tone pitch data KC corresponding to the angle data KD. The tone pitch data KC and the key-on data KOD are supplied to a musical tone signal generating circuit 19. On the other hand, when the musical tone control circuit 18 detects that the key-on switch 11 is turned off, the musical tone control circuit 18 generates and outputs key-off data KFD to the musical tone signal generating circuit 19. When the musical tone signal generating circuit 19 inputs the key-on data KOD, the musical tone signal generating circuit 19 generates a musical tone signal having a tone pitch corresponding to the tone pitch data KC so as to drive a speaker SP. On the other hand, when the musical tone signal generating circuit 19 inputs the key-off data KFD, the musical tone signal generating circuit 19 stops generating the musical tone.
As described heretofore, when the player holds the stick S by his right hand and depresses the key-on switch 11 while the player swings up his right arm, this musical tone control apparatus shown in FIG. 6 generates the musical tone having the tone pitch corresponding to the arm swinging angle of the player. Then, this musical tone control apparatus stops generating the musical tone when the player releases the key-on switch 11.
In order to properly generate the musical tone having the desirable tone pitch when the player plays a musical tune having a rapid tempo, it is preferable to set a range of the arm swinging angle of the player relatively narrow. In this case, a relation between the arm swinging angle and the tone pitch to be generated must be changed in accordance with a changing range of the arm swinging angle. However, the former musical tone control apparatus can not change such relation between the arm swinging angle and the tone pitch to be generated.